Emma and Mary Margaret, with the aid of Mulan, Aurora and brave knight Lancelot, attempt to find a portal that will bring them back to Storybrooke. But a dark force threatens their safe return. And Henry tries to talk Jefferson into reuniting with his daughter. Meanwhile, back in the fairytale land that was, on the eve of meeting Prince Charming's mother, King George poisons Snow White, and the only antidote lies within the waters of the Lady of the Lake